(24) Gene Regulation: Tumour Suppressor Genes | A-level Biology | OCR, AQA, Edexcel

Tumor Suppressor Genes

• Definition: Tumor suppressor genes are specific types of genes that encode products essential for regulating the cell cycle.

• Function: They primarily inhibit cell division, acting as a checkpoint to prevent uncontrolled growth, which can lead to cancer.

Role in Cell Division

• Balancing Act: There is a crucial balance between signals that encourage cell division (necessary for growth and tissue repair) and signals from tumor suppressor genes that inhibit cell division.

• Importance: This inhibition helps control how much cell division occurs, preventing potential tumor formation.

DNA Repair Mechanisms

• DNA Damage Repair: Tumor suppressor genes are also responsible for repairing DNA that has been damaged, particularly from exposure to mutagens.

• Mutagens: Mutagens are environmental agents, such as chemicals and radiation, that can change the DNA structure, leading to mutations.

• Mutation Definition: A mutation is defined as a change in the DNA sequence that can disrupt normal gene function, potentially leading to cancerous growth.